Power transmission device



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POWER TRANSMISSION DEVICE S5. so

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May 28, 1940.

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2,202,378 POWER TRANSMISSION' DEVICE Joseph Hertrich, Mantua, N.Application May 14, 193s, serial No. vases 13 claims.v (ci. 74-330) Thisinvention relates to improvements in pow- It is also a feature ofnovelty of the presentl er transmissionsystems, but more particularlyinvention to effect automatic shifting from one to variable speed powertransmission systems and speed to another both in acceleration anddeapparatus for operating same. f. celeration.

Hitherto power transmission systems have been It is'4 an additionalfeature of novelty of this 5 characterized by a number of disadvantages.In invention to provide a single shifting lever for the case ofautomobiles an appreciable time pethe multiple control and operation` ofv.the gear riod is involved in the hand shifting of gears. shiftingmechanism and the friction-clutch The clashing of gears can only be doneaway with mechanism. by the more skilled' drivers. In addition, shift-Another feature of novelty is v.the provision 10 ing of the clutch everytime a change in speed is `of a shifting mechanism so designed andlarmade, requires further time periods. ranged as to cause the automaticdisengagement These general disadvantages in the prior powofthe frictionclutch when' gearsare shifted. er transmission systems are done awaywith by Another feature of novelty is the provision of. theconstructions hereinafter to be described, in means for reversal ofpower flow by utilizing 15 which the older speed boxes are now modifiedto certain gears for the transmission of power in permit the operation'of the vsame and effect ltwo directions when operating different ratios.change in speeds through gear ratios solely, or Further features ofnovelty include means for for the mostl part, by the action ofappropriate manually controlling the automatic clutching at clutchingelements and without involving gear predetermined engine speeds andassociating 20 UNITED STATES PATENT oI-Flcal shifting mechanisms.necessary regulating mechanism with dashboard 'I'he new constructionsherein permit more control members. speeds to be utilized and fasterchange from Another-,feature of novelty resides in the use one'speed toanother, and particularly in heavy of double friction clutches whoseelements are 5 vehicles. With all of these desirable conditions normallynot contacted and are kept in contact 25 and features automaticclutching may be utilized, by suitable operative means, includingmechanithereby eliminating the ordinary use of a foot cally,electrically or .hydraulically actuated clutch. mechanisms, or anycombination of the saine.

It is an object of this invention to provide var- These and otherdesirable features and :zdiable speed power transmission systems with avantages will be described inthe accompanying 3o great number of speedratios and a minimum, specification and illustrated in the drawings,cernumber of gears and operating parts. tain preferred variable speedpowerv transmission `Itl is also a feature of novelty of this inventionsystems being'shown incorporated in means for to provide in such systemsmeans for effecting effecting the same. These showings are given fasterchanges of speeds and with a minimum by way of example only, for, sincethe under- 35 amount of effort.. lyingI structural features may beincorporated A feature of novelty is the use of extra free inotherspecific systems, it is not intended to wheeling gear mechanism vtoincreasethe numbe limited to the ones' here shown, lexcept as ber ofgear ratios available. v such limitations are clearly imposed by the ap-A further feature of novelty of this invention pended claims. l is theprovision of means for providing -faster In the drawings like numeralsrefer to similar starting-pickups. parts throughout the several views.of which Another feature of* novelty of this invention Fig. l. is a.vertical longitudinal section,` part- I is'4 the provision forincreasing the top speed -ly in elevation turned 180 from its normalopratio for so-called overdrive, without yadding aeratin'g position, ofa variable speed power trans- 4 5` specialgear drive. i mission systemas adapted for motor vehicle Yet another feature of novelty ofthepresent use; 'invention is' the provision of a 4'gear vshifting lIiig.1a is a schematic diagram of the. power .mechanism actuated withoutaclu'tch pedal and flow obtaining in the transmission system of 0permitting the use of a brake vpedal for one rfoot Fig. 1;

and an accelerator pedal for 'the other foot. Fig. 2 is a. verticalsection through forward A further 4feature of novelty resides in theclutch mechanism taken on line- 2-1- 2 of Fig. 1; provision of meansforcausing the automatic Fig. 3isa vertical section through gear trainVengagement of the clutch, depending upon the housing and taken on line3-3 of Fig.. 1; combined effect of the motor speed and car speed. Fis. 4is a' vertical section through rear clutch 55 shiftv mechanism taken online l-I of Fig. l; Fig. 5 is a vertical section through a reversinggear mechanism and taken on line 5--5 of Figs.

Fig. 6 is a view similar to Fig. 1 showing elec- -trically actuatedclutch mechanism and modied rear clutch mechanism with two countershaftsfor additional power;

Fig. 6a is a schematic diagram of the power flow obtaining in thetransmission system of Fig. 6;

Fig. 7 is a vertical section through the magnetic clutch mechanism takenon line 1 1 of Fig. 6;

Fig. 8 is a vertical section through the gear housing taken on line 8 8of Fig. 6;

Fig. 9 is a vertical section taken on line 9-9 of Fig. 6 and showingreversing mechanism;

Fig. 10 is a vertical section, partly in elevation, of rear clutchoperating mechanism vtaken on line |0-|0 of Fig. 6;

Fig. 11 is a view similar to Fig. 1 showing a' modified form of powertransmission system and electrically-operated mechanical clutch;

Fig. 11a is a schematic diagram of the power flow obtaining in the,transmission system of Fig. 11; i

Fig. 12 is a half vertical section of the clutch mechanism of Fig. 11taken on line |2| 2;

Fig. 13 is a half vertical section taken on line I 3-| 3 of Fig. 11,showing the clutch plate control mechanism:

Fig. 14 is a vertical section taken on line y M M of Fig. 11, showingthe control for operating the thrust bearing of the clutch mechanism;

Fig. 15 is a vertical section through the main gear drive and taken online |5|5 of Fig. l1;

Fig. 16 is a vertical section taken on line lli- I6 of Fig. l1, andshowing the reversing mechanism;

Fig. 17 is a vertical section taken on line |1| 1 of Fig. 11, showingthe electromagnetic clutch control Fig. 18 is a vertical section, partlyschematic and partly in elevation, through a hydraulically controlledclutch operating device;

Fig. 19 is a vertical section, partly in elevation, of a control meansfor the device of Fig. 18 and taken on line i 9|9 thereof; Y

Fig. 20 is a schematic showing in vertical sectionjpartly in elevation,of an electric clutch operating mechanism with switch mechanismtherefor;

Fig. 21 is a vertical section of electric drum switch taken on line2I-2I of Fig. 20;

Fig. 22 is a vertical section of an automatic shifter taken on line22--22 of Fig. 20;

Fig- 23 is a schematic arrangement of the operative positions of thedrum-switch members of Fig. 20;

Fig. 24 is a partly vertical section shown 180 from its normal positionof ay power transmission and associated hydraulic clutch operatingmechanism and automatic control means therefor;

Fig. 24a is a schematic diagram of' the power ow obtaining in thetransmission system of Fig. 24;

Fig. 25 is a half transversesect'ion taken on line 2525 of Fig. 24;

Fig. 26 is a transverse section taken on line 26.26 of Fig. 24and'showing reversing-idler control; l i s Fig. 27 is a sectional viewof sliding `reversing idler gear taken on line 21-21 of Fig. 26;

Fig. 28 is a vertical section of combined gear and clutch control;

Fig. 28a is a vertical section taken on line 28a/ 28a of Figs. 28 and28h;

Fig. 28b is a horizontal section taken on line 28h-28h of Figs. 28 and28a;

Figs. 29, 29a, 29b, 30, 30a and 30h are diagrammatic showings of clutchand gear shift control positions;

Fig. 31 is a vertical section of an automatic governor control mechanismtaken on line 3|-3| of Fig. 24;

Fig. 32 is a vertical section taken on line 32-32 of Figs. 24 and 31,rotated 180, and

Fig. 33 is a vertical section, shown 180 from its normal position,through a modified gear box showing free-wheeling" gear mechanism toincrease number of gear ratios available.

-Considering the structure shown in Figs. 1 to 5, inclusive, theinvention herein will be considered with respect to an automobilegear-box arrangement disposed between sets of clutches.

'Ihe operative parts of the system will now be described. An enginecasing I0 is suitably joined to a forward clutch casing 20, which, inturn, is secured to a two-part casing 30, including a central chamber 3|and rear chamber 32. The forward clutch housing 20 has an annular flange2| adapted to mate with and engagea similar flange formed on the enginehousing, the members secured in any desired manner. A rear flange 22abuts against a flange 33 of the combination gear train and rear clutchhousing 30 The-'engine'shaft 40 is connected 'to a forward clutchmechanism 50, which, in turn, can be connected either to a main shaft 60or a hollow drive shaft 10. The shaft 10 may be connected to a gearshaft which is adapted to be connected through suitable gears to a rearhollow drive shaft 90. A rear clutch mechanism |00 can be operativelyconnected through suitable mechanism to either the shaft 60 or the shaft90. The rear clutch body |00 connects with the universal joint ||5through output shaft H0. The foregoing parts above generally designated,will be described-l more in detail hereinafter, both as to theirparticular structure and the mode of cooperation. The shafts 60 l0, 80,90 and output shaft ||0 are mounted in ball-bearings, designatedgenerally by the numeral |2 and supported in the housing 30, and betweenthemselves.

Considering the specific structures more in deu--A tail, the forward orengine clutch assembly 50 comprises a cover or clutch body portion 5Ihavling a central hub 52 secured to the engine drive starter ring gear53, a clutch-disk or friction-4 CTI plate 54, as well as a thrust plate55 secured to i the friction-plate by means ofstudsl 56 and nuts 56a.The thrust-plate l55 is mounted on and adapted to rotate with the innerrace of thrustbearing 51, surrounding and slidable along shaft 10.. Aclutch disk 50 is mounted on hub 50a,

which, in turn, is splined onto shaft 80 by means of ,splines4 00a.vAnnular clutch disk friction linings 50h are provided on either side ofthe clutch disk 00 and are adapted to engage the-inner face 50a ofclutch body 5| and the forward face of clutch-plate l34. A s econdclutch disk 53,1pro`vided Cil . end-plateA lill aaoasvs with frictionfacings 59h is Amounted im a hub 59a which is splined onto and-.adaptedtol rotate with shaft 10; being in engagement with splines 10a thereon.

The thrust bearing 51 is controlled by a contrch or operating lever 51amounted on shaft 51h'. The lever 51a is connected to a hydraulic plunger51d in cylinder 51o.' Taps 51g and 51h.l are provided at either end ofthe cylinder to permit the ingress and egress of hydraulicuid. Theplunger is provided with vsealing rings 5.1!. The Agear train` in therear housing 3| willA now be described.' Ilhe hollow drive shaft 10concentric with the main shaft 80 and ldisposed therearound, is mountedin ball-bearing races A|217. A second bearing |2c is mounted on shaftand e ages recessed annular end 12ofg'ear 1| formed on the end ftheshollow shaft 10. Gear teeth are provided on the circumference ofthis gear member 1|. The shaft 10 will be seen to be mounted on andsupported by the shaft 60 and is adapted to rotateconcentricallytherewith and independently thereof, and around its external supportingbearing. f A countershaft is mounted in casing 30, being supported inaligned relation in ball-bear-` ings |2d and |2e4 set in the casing 30.This countershaft is provided with gears 8|, 82, 83 and 84. Gear 8| isin mesh with gear 1| of drive shaft 10, while gear 82 is in mesh withgear 6| mounted on shaft 60 and keyed thereto, as indicated at Bla.Bearing |2f supports shaft 60 on the rearside of the gear 6| and thisbearing is munted in a boss 34 of member 30. An idler gear is mounted ona stud shaft 86 and is constantly in mesh with the gear 84 of coun-4tershaft 80. f 'A second concentric drive shaft 90 is mounted onbearings |2g and |2h` in the bosses 34, 85 of casing 30. Shaft is xed tothe inner race of bearing |2g and is provided with lsplines 9| adaptedto receive sliding gear 92. This sliding gear 'is provided withanannular groove 92a adapted to receive shifting-fork193 and be movedthereby along shaft 90 into1and1out of engagement with gear 83 or idlerygear-85. ,'I'his arrangement permits the use`0.f the gear train forreversal when desired. The-shifting-fork 98 is mounted on a shaft 94which shaft is controlled by control lever 95, the latter being keyed toshaft 91 set in journals 91a which are set in bosses 98 of .the casingcover 3|. The shaft 91,l in its turn,v is controlled by lever 98, whichis directly controlled by a hand lever, or other means, not shown. Thehollow shaft 90 is provided' at its other end vwith a vbearing |2ksupporting the clutch-plate or body |0| of clutch mechanism |00. The endof the shaft 90 disposed Within the clutch body 0, is splined, asindicated at 99, to receive-c1ut h disks |08, to be referred to more indetail hereinafter. i

' The clutch mechanism |00 comprises a clutch having a hub |0|a securedto the outer race of bearing |2lc. A clutch ring |02 is secured tothe/clutch end-plate and is provided with inner splines |03.l Anend-plate |04 is secured to the clutch body and is mounted on the outerrace' of bearing |2m, the inner. race of which is secured to the end ofdrive-shaft 60.-n A splined hub |05 is fitted onto-splines 84 of drive'-shaft 80. The hub |05 is also provided with outer splines |0517. Theend-plate |04 is provided withend-plate lugs |04a adapted to receiveaclutchcontrol mechanism. The clutch mechanism in` cludesa frictionclutch-plate |06 mounted on thrust-.bearing |20 having of the hydrauliccylinder |21. y

|21a. Taps |28 and |28a lshim an. By lever s shaft 90 to engage gear83.'

arms'll'l, which. in'tur'n, are mounted on vpins |01a and connected toand adapted to be operated by swivel levers |01b rotating on pins |01cset in between end-plate lugs |04a, above referred to. splinedfriction-disks |08 are mounted on shaft 99 and held in place by splines99 thereof. These disks alternate with other splined friction-disks|086-, which are mounted on splines |03 of the clutch ring. A second setof frictiondisks |09 are slidably mounted on splines |05b of sliding hub|05 and are adapted to frictionally engage' friction-disks |09a slidablymounted on splines |08 of the clutch rlng. 'I'he clutchplate orfriction-plate |08 of the double friction clutch |00 can vbe moved intoposition to cause the friction disks |08; |08a to mutuallyl engage orcan be r'noved to cause the frictional lengagement of friction-disks|09, |09a.

The mechanism for controlling the double friction-clutch includes thelever arms |01 and associated parts mounted on lugsk |04a of the clutchbody. These parts are adapted to be operated by secured onto the outputshaft ||0, which is secured to the inner hub |04b ofA end-plate |04 andabuttingthe outer race of bearing '|2m. The output shaft ||0 is mountedin a bearing |2n set in boss 81 of the clutchhousing 30. The universaljoint fork |`|5 is keyed onto the end of the output shaft and lockedthereon as by means l of -nut ||2. Theinner raceof thrust bearing the'inner race slidably.,

|20 is provided wltha'thrust-gro'ove |2| adapted to receive the driveorcontrol fingers |01d of the swivel lever control arms |01 controllingthe friction vclitch-plate |08. The thrust-bearing |20 is slidablymounted on shaft ||0 to permit trol mechanism is suspended from shaftmounted'on bosses or lugs |24a of the housing. The forks' are providedwith studs |23a adapted to engage slots or grooves in the outer race ofthrust-bearing |20. The forks are connected through shaft |24 to controlor operating lever |25 mounted on the outside ofthe casing and keyed toshaft |24. The control lever |25 is provided with a forked end |2511,having studs l25b adapted to engage hydraulic plunger |26 This cylinderis provided with a cover are provided on either side of the cylinder tocontrol the plunger. secured to the plunger to prevent hydraulicoperating fluid.

- The cooperation and'operation of the above assembly is substantiallyas follows1 When the hydraulic cylinder 51c is set in operation byintroducing pressure fluid through the inlet or tap 51g the plunger 51dis moved, carrying the operating lever 51a to the right.v 'I'his leverrocks on the shaft 51h and causes the thrust-bearing 51 to be movedtowards thev engine. The thrustbearing 51 carriesl with it thethrust-plate 54.

This latter #plate is moved towards the body of the clutch and grips thefriction facings 58b^of the friction disk 58 forcing the latter intofrictional engagement with the clutch body si.v The friction-disk 59being splined onto central shaft 60 establishes direct connection fromthe engine This power is applied through the shaftv91 and arm 95immediately controlling the shifter-fork l93. This operation places thehollow drive shaft 90 in the power train from the' engine throughtheVcentral shaft 60 and coutershaft 80. This power train is con-Y vthislongitudinal motion. A fork |23 of the con- Seal rings |29, |2911 areleakage ofsliding gear. 92 is movedon t I no Y established betweentheengine shaft and the output shaft. This hookup gives a low gear orrst speed.

To move into second speed the operation of the parts is as follows:hydraulic pressure is applied .on plunger 51d through tap 51h moving theparts to the left and carrying operating lever 51a inthe same direction.This operation causes the movement of thrust-bearing 51 to the right,

taking with it thrust-plate 55 and friction-plate 54. 'Ihis movementreleases clutch-plate 5l from engagement with friction-disk linings 58hof clutch disk 58 and jnoves it over into contact with clutch disk 50which is splined onto hollow drive shaft 10. 'I'he pressure of plunger|28 is .'n'ot changed, thereby maintaining the output shaft in directengagement with the second hollow drive shaft 00. It will be seen thatin this arrangement of the parts the power istransmitted from the engineshaft through the forward clutch to first hollow shaft 10 and gear 1|and gear 8| on countershaft 80 through gear 88 and sliding gear 92,second hollow drive shaft 90 and clutch-body |00 to the output shaft H0.

To ob ain third speed, which is thekdirect speed. e hydraulic plunger51d is again moved to the right by introducing pressure uid through tap51g; thrust-plate 55 is moved to the left,

freeing clutch-disk 50 and causing the reengagement of friction-plate54, clutch-disk 58 and clutch-body 5|, thus reestablishing connectionbetween engine shaft and central drive shaft- 60. Hydraulic plunger |20is also moved tothe y left by introducing pressure' fluid through tap|28a. Lever |25 is carried to the left, moving thrust-bearing |20 in.thesame direction and thereby causing friction-plate |08 to disengagefriction-disks |00, |08a and causing it to'engage in locking\engagement.Frictiondisks |09 are splined onto hub B05, which in turn is splinedonto the end of central drive shaft 60.

Thus, it will be seen that vthe engine shaft 4and an output shaft aredirectly connected without the intermediacy of any gear train.

The fourth speed, or overdrive, 4is obtained by releasingfriction-ciutch disk 58 and locking clutch-disk 59, which as alreadynoted, is accomplished by introducing pressure fluid into inlet 51h ofhydraulic cylinder 51e. The rear clutch mechanism is maintainedas indirect connection, establishing direct power connection between theterminal end of central drive-shaft to and the output shaft H0. Thepower train in this arrangement is from engine shaft to through theforward clutch 50, :first hollow drive shaft it, gear l1i, gear 8| andcountershaftd to .gear'02,

e and gear 6| directly secured to the drive shaft 60,

which, as noted; is directly connectedto the out- ,Dut shaft.

The method of securing the two reverse speedsA with this improvedclutch-and-gear vassembly will now be described. The initial step inthis arrangment is to move sliding gear 92 into engageaaoasvs ment withidler gear 05 by means of hand lever 88. 'I'his operation brings thereversing gear train into use. The first reverse speed is lobtained bydirectly connecting the engine shaft with central drive-shaft throughclutch-disk 8. This, as previously noted, is accomplished by introducingpressure fluid into hydraulic cylinder 51e through tap l51g. In likemanner, pressure fluid is introduced into hydraulic cylinder |21 throughtap |28, causing thrust-bearing |20 to be moved to the right andfriction-plate |06 to lock friction-disks |08 and |08a together, thusconnecting second hollow drive shaft 90 through clutch-body |00 to theoutput-shaft |0. In this arrangement it will be seen that power flowsthrough first clutch-body 50, central drive shaft 60, gear 82,countershaft 80 and gear 84 to idler gear 85, which causes a reversal ofpower flow through sliding gear 02 to second hollow driveshaft 00,vcausing this shaft to counter-revolve with respect to centraldrive-shaft 60. 'I'his reversed power flow is transmitted by hollowdrive Vvshaft 80 to the double-friction clutch-body |00 and output-shaft||0.

For the second reverse speed the first clutch is reversed, releasing thedirect connection from the engine shaft to the central drive-shaft 60and establishing direct driving connection to the engine-shaft throughthe first hollow drive-shaft 10. In this arrangement the power now isthrough the rst clutch system 50 to the hollow drive-shaft |0, gear 1|,gear 8| and countershaft 80 to gear 84, idler gear 85 and reversingdirection. 'I'his idler gear engages sliding gear 92, causing reversalof direction of the rotation of the second hollow drive-shaft 90, whichis locked in driving engagement with friction-disks |08,

l|080. of clutch member |00, whichmis in direct connection with theoutput shaft.

It will now be seen that the transmission system described in andillustrated in Figs. 1 to 5, inclusive, provides a mutual interlockingof the parts so that for each forward speed each of the double frictionclutches in clutch-body |00 must be locked in one or the other position,and, at the same time, each clutch can only be locked in one position atany given time. This gives a fool-proof clutch-shifting arrangement'forforward drive, withoutany speed-interlocking device.

' The specic friction clutch construction should be strong enough forthe purpose desired and can be operated hydraulically, as shown, or byany other method. These operationsfcan be accomplished manually orautomatically. There is a practical and very important dierence in theoperation of the-.two-friction clutches 50 and |00. The first clutch 50takes the engine torque directly, at all times. This clutch is sodesigned and built as to work under variable' pressure and to permit anydesired slidingggf the friction disks for satisfactory operation of thecar. To accomf plish this purpose the friction surfaces, as shown, areand must be large erfough to prevent rapid wear and 'overheating causedthereby. In addition, the clutch members must be of correct size andldesign to properly and rapidly dissipate any frictionally engenderedheats. The variable pressure on the input clutch members can be obtainedby varying the hydraulic pressure on hydraulic plunger 51d of operatingcylinder 51e. Clutch |00 and its parts, constitute essentially a lockingdevice. Smaller surfacesare required forthe 'torque transmission and nosliding or s v i l preferably and desirably `is provided with arenariall l slipping of the parts is required. As the result of these factors aconstant highsurface .pressure can be applied to the contactingsurfaces. Thus this xity of parts and operation makes it pos- 'sible touse a small diameter clutch-body with any kind of friction-plates. Thevariation of the friction coemcient with speed has noappreciableinfluence on the operation of this output clutch.

The transmission system above described gives four forward speeds andtwo reverse speeds, although only requiring leight gears.' Each gear isused for at least twodiiferent speeds. It is to .be noted, however,thatall forward speeds are obtained' without shifting gears and solely'by means of operation of the clutch members, and in the sequence notedimmediately above. vIn addition, only one shifting of gears is requiredfor the two reverse speeds. These advantageous features are furthervenhanced by the fact that the changes from one speed to another are bothfast and smooth. The inclusion of an over-drivejn this transmissionsystem provides for a lower engine speed at high speeds of the vehicle.i

It will, of course, be understood that anyv arrangement of gears may beutilized to give desired speeds, and in any desired sequence ofoperation.

Referring now to Figs. 6 to l0, both inclusive, there is shown a modiedpower transmission system and assembly. In this modification, now aboutto be described. the gear box proper is provided with two countershaftsto permit the use of the assembly for heavy-duty purposes, as well asfor ordinary light-car use.

In the form shown schematically in Fig. 6a and in detail in Fig. 6, atwo-or-more-part casing 200 a forward annular flange or flanges adaptedto abut or engage an engine body, a central partition member or membersl202 dening a forward magnetic clutch chamber 203 with the engine body,and a second or rear partition wall 204 forming an inner gear cham? ber205 with the external walls and the first -partition wall 202. adaptedto house the gear train and to be substantially hermetically sealed sothat the gear box may befilled with suitable lubricants. The

partition walls 202 are apertured to receive xed shafts 80h and 80d andthe walls .204 are also y apertured to 'receive the same shafts. The endor partition wall 204 has a central hub section 206. This member is alsoprovided .with a pair of lugs or arms 201 which willbe referred to morein detail hereinafter. A rear clutch housing 220 receives the rearclutch mechanism and is secured to the gear box 200, being abuttedagainst and secured to the wall 204 thereof. The casing 220 is providedwith rear hollow extensions 22| adapted to support and r'e'ceivebearings |2p and |2q, respectively, which serve as supports for theoutput shaft |30.

'Theforward chamber 203 houses a 'magnetic clutch a connected to enginedrive shaft 40. This clutch has a rear cover 52a terminating in a collar52h concentric with the first hollow drive shaft 10. The usualfriction-disks 50 and 59 are mounted on the ends of central drive shaftand hollow shaft 10, respectively. .A friction clutch-plate 54a isdisposed in the clutchlbody 50a and adapted to engage'splines 54h formedtherein. The body portion 50a ,of lthe clutch body' is provided with an'annular channel containing" a solenoid or magnetic winding 50h.

TheY cover plate 52a issimilarly 'channeled to The so-formed chamber Lisreceive a like solenoid 521;. -These solenoid windings are grounded,to the respective parts of the clutch housing, as indicated at 50c and52d, respectively. Leads 50d and 52e connect -these solenoids `tocommutator rings 50e and 52f, respectively, mounted in insulating ring52g on collar 52h of the clutch casing. Brush members 50j and 52h aresecured in lug or stud 208 of gear casing wall 202 and are suitablyinsulated. These brushes are provided with leads 50g and 50h connectedto suitable switch mechanism, as

shown generally in Figs. 20,

ground connections of the clutch body are also i connected in a mannerto permit the solenoids 50h and 52c`to be alternately connected whendesired. The arrangements just described provided. a magnetic clutchcontrol for th'e input end of the unit or the forward clutch mechanism.As wasv previously noted, 1a certain amount of flexibility or variationin pressure between the vclutch members and the driving .and drivenmembers, is desirable in the clutch connected directly' to the engineshaft. This' can bereadily taken care of in present instance by varyingthe amounts of magnetic flux developed in the solenoids 50h or 52o. Theclutch casing members are preferably made of ferrous materials or othermaterials having suitable magnetic permeability to permit the same tocooperate with the clutchplate 54a to effect the frictional holding qfthe friction-disks 58 and 59 in the clutch mechanism.

The gear train in the present modication comprises the usual gear 6|mounted on central drive shaft 60 and gear 1| mounted on hollow drivevshaft 10. The gears' 0|, 82and 83, previously described, together withreversing gear 84 are mounted on a hollow shaft which is tatabiy mountedon a fixed vshaft 80h su'ppor d between the parttion walls 202, 204 ofthe gear chamber and supported for rotation on the shaft by means ofbearin'gs 80e. A second countershaft 00d is supported "in a mannersimilar to shaft A 80h and oppositely thereto in alignment with shafts60, 10 and 90 and opposing andebalancing the power thrust rotary hollowshaft 80 and associated gear members. This lshaft rotatably supports ahollow gear shaft 80e through bearings 80e. The hollow 'shaft 00o isprovided further with gears Blain mesh with gear 1I of `hollow driveshaft 10, and gear 82a in mesh with gear 6| of central/drive shaft 50.As power is delivered tothe gear train througi mese gears 1| and slg'itwi11 be seen that the provision of a pair of countershafts with gearsconstantly in mesh, will provide a static balance between the shaft 80h'and 80d and the hollow gear shafts 80a and 80e, preventing any bucklingdue to unbalancedloads on one side ofthe gear chamber, and thuspermitting heavier loads to be imposed on the gear train. The usualreversing mechanism is provided.

The, rear clutch housing 220 contains a rear clutch mechanism 22| havinga -dished body portion 222 anda central apertured hub- 223 and anannular cover-plate 224.. The hub 223 is secured to the output shaft |30in the usual man'- nerand receives the end bearing |211 for the centraldrive shaft 50. The annular cover-plate 224 is provided with'a pluralityof lugs 225 sup-'- porting stub shafts 226, which serve as pivots foroperative levers 221 of the clutch-plate 23,0. The clutch-plate isconnected to the levers 221 through vthe arms 220 'fulcrumed on shafts220m and secured to the clutch-plate 230 by means normally deliveredthrough l -this modification, as before, the utilization of a.

- tion disks 58, central drive shaft 50, gears 5|, 52,

v248 therein. The 'teeth 2l respectively mounted on splined hubs 233,233, which splines are adapted to slidingly engage splines 99 and 64formed on the ends of drive shafts 90 and 50, respectively. f

The clutch mechanism` 22| is controlled by thrust-block mechanism 230which includes an 'inner race 24| having transverse teeth or rackmembers 242 adapted to engage like members 221:1, formed in the bottomof clutch arm 221. The outer race 233 of the thrust block'240 is slottedto receive studs 243. of yoke 245 which is iulcrumed on stub shaft 2I1ailxed in lugs 291 of the gear casing partition 20|. The yokearms 245converge to form a common Y or bottom leg 246 which is provided on. itsbottom with an arcuate arm or rack 241 ha' g transverse teeth of rack231 are adapted to engage pinion. teeth 252 of a reversing motor 250.'I'he pinion gear 252 is mounted on shaft 25| of the motor and thelatter is con- 'nected through 253 to a reversing switch shown in Fig.20. The gear.casing may be provided with locking means such assplugs orend caps 202a and 204a, respectively adapted to lock bearings |2b and|211, in operative position and are provided with means to preventleakage of lubricant from the gear chamber 205,

It will be seen that by utilizing the reversing motor 250 the lever 245can be moved to the right vor to the'left, to cause the operativeengagment of either driving shaft 90 or driving shaft v91| with theclutch 22|, and the output 4shaft |30.

The operation of the 'transmission system just described, is as follows:When a suitable switch is thrown so-that current is passed throughclutch lead 50g, solenoid 5017' is energized and -1 clutch-plate 54amoved into frictionai engage' vment with friction-disks of clutch-disk58. This connects the engine shaft directly withtlie central drive shaft60. If' current is applied through lead 50h, solenoid 52e is energizedand moves clutch-plate 54a into frictional engagement with friction-disk59, thereby connecting the engine shaft through the clutch body tohollow drive shaft 10. As noted 'before, second clutch body 22|, in itsturn. and usually in advance of the input clutch members, iselectrically controlled through'the reversing motor 25| to permit directtakeoifof power from central drive shaft 50 or second hollow drive shaft90, which is connected through the gears mounted on gear. shaft 00a tothe first hollow drive shaft 13. In' the reversed positions the` slidinggear 92 of hollow drive shaft 90 engages-the idler gear of the reversingmechanism. As already noted the.slid v ing gear 92 is moved intoforward-drive position on engagement with gear 33 or into reverse drive:,aoaavs of bons 22s.. The two'ciutcii disks 23|, :more

engine shaft u, oiiitono body no, friction disk n, honow drive shaft u,gears 1i, u, gear shaft 30', gears 93 and 92, second hollow drive Shaft90, friction disk 23| and clutch body 22|- to output shaft |30.

For direct drive, 'both clutches are reversei Motor 235 is reversed, andthereby locks friction disk 232 into operating engagement with secondclutch body 22| and output shaft |30 connected thereto. Friction disk 53is locked to clutch body 50a, thereby connecting central drive shaft 93directly to engine shaft I0.

For the fourth forward drive or so-called overdrive", the first clutchis operated to lock frictlon plate 59 into engagement with the clutchbody 50a, thereby switching hollow drive shaft 10 into operativeengagement with engine shaft 40; second clutch 22| remains operativelyconnected to central drive shaft through friction disk 232. Power istransmitted from first hollow drive shaft 10 through gear 1| to gear 3|and lla, 92a to se 5| and cent1- al drive shaft 30 to the rear clutchbody 22|. It is to be noted 'that no interlocking device is required forforward speeds, as each speed requires a definite cooperation of thepartswhich is effected through the shaft 'in the association of theseveral clutch parts without requiring any shifting of gears. Astheclutch parts are alternately arranged and only one in each of the twogroups can be operatively connected, there is no opportunity for troublearising from improper or double connection of parts in any of the clutchdevices.

For reverse speeds the sliding gear 92 is movedinto engagementwith theidler gear 85,*and fric- E gear shafts 30', 33a and gears 0 2 and tiondisk 23| of second clutch 22| is locked to' -hollow drive shaft 90. Forthe first reverse speed,

friction disk u of c1ut'oiisna is looked. Power l flows through enginedrive shaft 30, clutch body 50a and central drive shaft 50, gears 5| and32,

' hollow gear shaft 00', gear 84, idler `gear 35 and sliding gear 92,second hollow drive shaft 99,

position by engagementwith the idler gear 35 by means of fork 93 ofthegear control mechanism. It will'be again noted that in the operation ofgear ratio is effected by appropriate combinations of the clutchmembers, the single, positive gear control being'effectedthrough.sliding gear 92 to determine forwardspeeds or reverse speeds.

It will be seen that for rst speed, power is transmitted from the engineshaft 40 to ,output shaft |30 through the nrst clutch body 50a;fricfriction disk 23| and clutch body 22| to output shaft |30. For thesecond reverse speed friction disk 59 of clutch body 50a is lockedthere- `by connecting hollow drive shaft'10 to the engine shaft 40through the clutch body' 53u. Power is transmitted from shaft 1l tolgear1| and gear 3| to gear shaft 39', gear 3|, idler gear 35, sliding gear92,- s'econd hollow drive shaft 93, friction disk 23| and clutcgbody 22|to out- It will be noted that with this transmission four forward speedsand two reverse speeds are obtained. This transmission has Ythe sameadvantages as the one shown in Figs. 1 to 5. The chief difference is inthe electrical operation of the clutches and the inclusion Aof anadditional countershaft in the gear box, Thisadditional countershaftpermits the increase of the horse power capacity of -the transmission.If the strength factor on the gears has to be increased,

' .the number of gears on the hollow countershaft 00a may becorrespondingly increased. In such case a' second reverse idler can beinserted to mesh with this gear on the second countershaft.

The first clutch, already described, is a variable pressure clutchtopermit smooth action when engaged. The second clutch can be a,constant high-pressure clutch and does not have to be designed to takecarof heat dissipation.

Considering the double clutches generally, it is to be noted that thedetails of the operative mechanisins therefor may be varied in anydesired which, in turn, are splined of thrust bearing |54 br the dutchbody. y

Referring'now to Figs. 11 to 17, there is shown a speed transmissin witha number of ratios. This transmission is characterized bytwo inputshafts and a double friction mechanical clutch which' is preferablymagnetically operated. The gear train is provided with a double slidingclutch. In this assembly, which is primarily designed for heavy-dutyvehicles, such as engine-driven cars, trucks, buses, and the like, theengine `shaft is connected through a double clutch body alternately to acentralydriving shaft and a hollow drive shaft.,- The central ,driveshaft may be directly connected by means of a double clutch to theoutput shaft or to the gear shaft in the gear box. -This latter shaftmay be connected through a sliding gear on :the output shaft and areversing idler gear. This combination gives dou- -ble the number ofspeeds in a transmission without making the operation of the same at allcomplicated and provides a faster pickup, enabling the most emcient useof the engine power and a longer service ofthe engine. As noted, thetransmission system about to be described, is particularly adapted foruse in trucks and buses.

This particular transmission provides six forward speeds and two reversespeeds. There are but three shifting operations required for the sixforward speeds. The change from first' to second speed, from third to'fourth speed, and from ,direct speed to overdrive, can be effected"swiftly and without slowing-the is of marked advantage on the startingof the vehicle, also when going uphill and in uneven country, as well asgoing down steep grades and on long runs, wherethe overdrive"can be usedto slow down the engine. These features of novelty and advantageinemcient operation, upkeep and longevity of parts, will be more clearlyunderstood by reference to the assemblyl of the various features. y

The transmission system incorporated in the showings of Figs. 1l to 17,comprises a gear box or oil-tight housing .300, of two or more parts,

abutted against and fitted to the adaptor or fore ward clutch housing20, which in turn is secured to the engine casing l0. The input clutchmech'- anism comprises the usual' clutch body 50 which is preferably ofdish or cup shapey and secured to the engine shaft 40 and is ofsuflicient weight to permit it to serve as a flywheel, which may also betrue of the other input clutch` bodies hereinabovedescribed. A startingring gear 58 is secured `to the clutch body. An annular cover member 52is secured on the rear of the clutch body and is provided with apluralityof lugs 52k in which friction-plate control arms |55 arefulcrumed on stubeshafts |5I. These control arms are provided witharcuate gears |52 on one end, meshing with suitable teeth |53 on theinner race upper ends are provided with forks |55 carrying stub shafts|51, on which' second lever arms |50 are fulcrumed, which armsclutch-plate 54a in any suitable-manner 4as by means of bolts |59. Theusual friction disks 58 and 59 provided with friction facings 58h and59h are mounted, respectively.,

on central drive shaft |50 and'hollow drive shaft |`|0. These -driveshafts are mounted in bushings |2a, |21 and |211,

|2c, respectively secured in the clutch body and in e Thusthe clutchcontrols may be operatively connected on either side e ported on lugs orarms |5511 'gear housing 300. 4yoke has a depending lever longitudinalmovements on splines |9| engine dOwl-'L-v Thisv is adapted to be movedby fork of thrust block |55 and the are secured to the o'n hubs 58a and59a,v

'solenoid can be :en

. e 7 the gear casing partition. The thrust-blockV |55 is slidablymounted for free and over hollow |5511 mounted on stub shaft |55cwhichis sup The thrust block actuating arm |55e which is suitably connectedtoa magnetic clutch-operating device 950, which will be described morein detail hereinafter. Hollow. drive shaft is connected to solid gearshaft 80 through gears 8|. Gear shaft 80 is mounted in aligned bushings|2d, 12e, set in gear casing body 800. This gear shaft is tted withgears 8|, 82, 88, 84 and 84a. Gear 84a is constantly in mesh withreversing idler gear 85 mounted on fixed stubshaft 85 set in the gear y.y e. The -shaft |90 in the serves the dual function of -a transmissionshaft and an output shaft. The forward end is mounted in ball-bearingrace |2s set for free rotation in l the terminal gear |8|` of centralinput shaft |50.

This gear |5| is provided with clutch vjaws |5|a adapted to engage likejaws I5 Ib on double clutch |52. 'This double clutch member is splinedfor of shaft |90. A gear L83I provided withiclutch jaws |93a engaginglike jaws |52 is mounted for free rotation on shaft |90., being abuttedagainst collar |90a formed thereon. This gear |98 is constantly in meshwith gear 03 of. gear shaft 80. The usual sliding gear 92 is mounted onsplines ||a on the shaft |90 and 500 forwardly into engagement with gear8| of gear shaft 80 Lor rearwardly into engagement with idler gear 95 ofthe reversing gear mechanism.

a The solenoid controlled anism 350 will now be \,described. Thissolenoid mechanism comprises a' core member 85| flxedly mounted on shafting 353 of the solenoid and is connected to lever' or yoke arm I55e andlto interconnected control pedals 554, 355, through lever arms 355, 951(The control pedals are mounted on lugs 28, 28, formed on adapter casing20.- The solenoid casing 353- is provided with solenoid winding 358having a plurality of' taps 858, formed in b1ocks or segments and havingtheir terminals set in insulating block or plate 85| mounted in switchcasing `360, set on and secured to the solenoid casing or formedintegral therewith. The switch mechanism comprises-a switch or slide rod382 slidably mounted in the switch casing 350 and provided with ahand-controlled lever 3,53 suitably. fulcrumed to the switch lever. Thecontrol lever maybe mounted readily adjacent the steering wheel. Italsomay be mounted directly'on the switch box mechanism, and the latterconnected-.through suitable cable connections tothe solenoid casingproper. An insulating block85l is xed on sliding shaft ed on vthe switchcasing, one of the terminals being insulated therethrough as by means ofinsulating bushing 85517,. theother terminal being preferably groundedtothe casing.. It will be seen that by moving 'the switch block over thesolenoid commutator segment the various portions of the ergiled'. andwith varying drive shaft |10, and'theouter race |'55a thereof issuspended from yoke arms H0 of gear shaft clutch operating mechonv theinput side f present arrangement 9,52 which passes through cason thesteering shaft casing or I of thesolenoid in definite,

amounts of current flowing therethrough, whereby desired variations inmagnetic iiux can be induced in the solenoid; This variation in positionand density of the magnetic ux in the solenoid causes the solenoid coremember to be moved to various positions in the solenoid casing and carrythe clutch actuating rod 352 with it. 'In this movement yoke arm |55e ismoved predetermined distances and carries the thrust block to one sideor another, and this thrust block movement causes clutch-plate 54 tolock friction disks 58 or 59, respectively, to the clutch body 50. Noautomatic return of levers 354 and 355 is required, as they areinterconnectedl The operation of lever 354 brings lever 355 into itsoperating position, and vice versa.v Foot pedal 355 may serve in anemergency as a declutchlng member and the clutch can be engaged by thefoot pedal 354 if the current supplied to the solenoidfails. Normallythe solenoid is energized at all times. Lever 354, when pressed, movesyoke arm |55e and thrust block |54 to the left as viewed in Fig. 11,thus moving clutch plate 54 into contact with facings on friction disc59. This occurs through movement of the lever around its fulcrum on lugs29, during which motion is transmitted to yoke arm |55e by lever arm356. At the same time, foot lever 355 is moved around its fulcrum onlugs 28, in a direction vopposite to lever 354, by the action of link orarm 351 pivotally connecting the end of lever 355with-yoke arm |55e.Thereafter, lever 355 may be pressed to release the clutch by moving theyoke arm. and thrust block |54 to the right, the limit of such motionbeing at a point wheregarm 351 is substantially in alignment with arm|55e. At this point the clutch plate 54 is in a neutral position, and inthe course of reaching it lever 354 has been restored to its initialposition. The neutral position is obtained by moving the solenoidswitchto the center of' the switch box so that the contact fingers 365,

tween the two contact fingers.

366, rest on insulating portions of the device and are not in currentcontact with commutator or switch segments.

As already noted, gear 8| is in constant mesh with gear |.1| gear 82 isin constantl mesh with gear |6|; gear 83 is in constantmesh with idlinggear 93;'andgear 84a is in `constant mesh with reversing idler` gear 85.For forward speeds sliding gear 92 meshes with gear 84, while forreverse speeds sliding gear 92 meshes with reversing idler gear 85.

The operation of the clutch mechanism gen-- erally is as follows. Asnoted, an electric current is always impressed on switch Aterminals365a, 366a. When the switch lever 363y is in neutral position thecontact fingers 365, 366 do not make contact with -the coil terminalsand no current ows through the solenoid. When the operating lever ismoved to the left contact fingers 365, 366, touch someof the contacts359 at the right ,of the solenoidmechanism. An 4electric current isthereby caused to flow through that portion of the solenoid which is in'the ield be- I'he magnetic iiux so created pulls the iron core 35| -ofthe solenoid in the center of the magnetic eld. When the control leveris moved -to the left the center of the magnetic field is shiftedaccordingly and the iron core carried with it. The lever pushes thethrust block andA control lever mechanism and the thrust bearing ismoved to the left or right, carrying the frictionclutch plate with it.Thus, when the switch control lever is moved to the right the iron.'core 4of the solenoid moves lwith gear 84. Switch control lever 363 ismoved to one side to cause friction disk 58 mounted on centralinputshaft |60 to be locked to the clutch body 50, thereby connectingthe input shaftA |60 with the engine shaft 40. Power ows from the engineshaft through the clutch body and the central input shaft |60 throughterminal gear |6| to gear 82 mounted on gear shaft 80, thence throughgear 84 to sliding gear 92 and output vshaft |90 to universal ioint ||5.

For the second speed the forward clutch is reversed to lock frictiondisk 59 to the clutch body. This connects the hollow input shaft |10 tothe engine shaft 40 through the clutch body 50. The power ow is from theengine through the clutch body to the hollow input shaft and itsterminal gea;` |1| to' gear 8|, gear shaft 80, gear 84, sliding ger 92,and output shaft |90 to universal joint Il 'L For third speedslidinggear 92 is put in neutral and double clutch |62 is engaged withvgear. |93 which is mounted for free `rotation on output shaft' |90.Friction disk 58 is locked in position in the clutch body. The powerflow is, therefore, from the engine shaft through the clutch body tocentral input shaft |60,`terminal gear gear 82, and gear shaft 80, gear83, idler g ar |93, clutch body |82, output shaft |90 to the universaljoint l5. p

For the fourth speed, hollow input shaft |10 is locked to the clutchbody by lfriction disk 59. Power is transmitted from the engine shaftthrough the clutch body to thel hollow input shaft, thence .through gear|1| to gear 8| and gear shaft 80, gear 83, idler gear |93, double Forfth Speed the double-clutch body |52 is y moved to engage with terminalgear 6| on central input shaft |60. This directly connects'the alignedinput and output shaft |60 and |90. Clutch disk 58lis locked to theclutch body, thereby establishing direct connection between engine shaft40 and central input shaft |60. 'Ihis is the direct speed. V

For the sixth or overdrive" speed, hollow input shaft |10 is locked tothe clutch body through friction disk 59. vThe power flow is thus fromthe engine shaft through the clutch body and hollow input shaft |10 togear shaft 80, and gear 82 to terminal gear I 6| of input shaft 60 anddouble clutch |62 to the output shaft |90 and the universal joint ||5.

For the rst reverse speed sliding gear 92 is moved to engage withreverse idler gear 85; central input shaft |60 is connected to theclutch body through friction disk 58. Power flows from the engine shaftthrough the clutch body, cen- -tral input shaft |60 terminal gear |6|,gear 82, gear shaft 80, gear 84a, reversing'idler gear 85, sliding gear92 and output shaft |90 to the universal joint ||5.

For the. second reverse speed clutch disk`59 is locked in positionconnecting' hollow input shaft |16 to the clutch body. The power flow inthis rapid, efficient and positive in operation.

clutch shift lever may be mounted directly on the tures above cited.

operation is from the engine shaft through the clutch body and hollowinput shaft to the gear shaft 80 and gear 84a to reversing idler gear 85 and sliding gear 92 to output shaft |80 and universal joint ||5.

The arrangement immediately above described gives six forward speedsrequiring only three shifting operations. The clutch shift controlmechanism gear is operated bythe linger andis This gear shift lever.

As noted hereinabove, and more particularly with respect to themechanical operation of clutch 50 and clutch |00, the actuation of thecontrolling levers or operating members of such clutches may be effectedby hydraulic or like means. Referring more, particularly to Figs. 18 and19, there is shown hydraulic clutch-operating means and valve controlsfor same. The clutch-operating mechanism includes the clutch leveroperating motors or cylinders 51e and |21, both previously described,and severally adapted to operate clutch-plate operating levers 51a and|25', respectively. These clutch operating mechanisms may be directlycontrolled through a single valve means designated generally by thenumeral 500. The valve 500 is connected to piston cylinder 51e byconduits or pipes 50|, 502 and to piston cylinder |21 by pipes orvconduits 503 and 504. The valve, proper, comprises a body portion 5|0 ofgenerally cylindrical shape having end closures or caps 5|0a, andprovided at one end with a flat- .tened T or cross-extension having lugsor bosses 520 adapted to receive valve piston actuating andlockingimeans which will be described more in detail her inafter. Thevalve body 5|0 iswprovided wl a plurality of taps adapted to permitingress and egress of actuating fluid into and out of the valve body anddesignated by the numerals 5|| to 5|9, both inclusive. A valve piston530 is fitted in the valve body 5|0 and is so designed as topermit'appropriate fluid connections to be made between the severaapertures described immediately above. This iston or valve memberincludes a body portion 53| of generally cylindrical configurationand-adapted for sliding 'fit in the interior of the valve body. Thepiston member is provided with a plurality of surface depressions ofgenerally annular shape and of varying width or depth, adapted to spansimilar depressions formed o the interior wall of the valve body. Asshown, he valve body is provided with a plurality of interior annulardepressions 5|5a, 5| la, 5|6a, 5|2a, 5|1a, 5|3a, 5|8a, 5|4a and 5|8a,severally connecting Iwith like-numbered aper- Thevalve piston 53| ismachined or otherwise formed to give a plurality of annular depressionsor valve portions 532, 533,

534, 535, 536 and 531, whose function and cooperation with theinternal'annular depressions of the valve body-will be considered in thediscussion of the operation of the valve.

The valve piston or operating member is operated by a'control lever -540in the following manner. A spindle or shaft 54| is formed on one end andas a continuation .of the valve piston 530. This section, or mmber 54|,may be generally reetangulanin'cross-section and is provided on the topsurface with a toothed rack 542 adapted to be engaged and moved bytoothed wheel 543 keyed on shaft 544, which is'mounted for rotation vinboss 545 formed on the end of the valve body 510. The rack and wheel arekeyed to the hand Ylever or other control 540. The shank or spindle caps551. nately adapted to engage the locking notches 550 chamber 51| of thesection 54| l is provided further with staggered lateral depressions550, 55|, 552, 553 and 554 severally adapted to be locked by opposedspringurged locking members 556 disposed in the bosses pins 556 aregenerally hollow and have coil springs 558 disposed therein and inabutment with the end The locking members 556 are alterto 554,respectively, when the valve piston 53| is shifted longitudinally of thevalve body by means of the control handle or lever 540 controllingtherack-and-pinion assembly 542, 543. By approprate movement of thecontrol. handle 540 any of the locking notches 550 to 554 may be movedinto locking engagement with the Vlocking pins 556, thereby setting upappropriate connection between the valve body and the associatedoutlets, .as will be described further in detail. vThe operating fluidsupply and distribution system for the valve 500, will now be described.V'I'he valve openings 5|5, 5|1 and 5|9 are connectedto a common headerpipe 560 which is in direct connection with a liquid reservoir 56|, andthrough a T-connection 562 to a pressure-regulating valve 510. Opening5|6 of the valve 500 is directly connected through pipe 563 to' innerpressure-regulating valve. Opening 5|8 of valveV 500 is connectedthrough pipe 564 to pressure pump 565, emergency pressure pump 580, andreturn to pressure-regulating valve 510. The pressure pump 565 may beconnected to the engine in any suitable manner and is tapped into andbetween feed line 566 leading from reservoir 56| and supply line 564. Anauxiliary pressure chamber or pressure accumulator 56|a may be tappedinto the line 564. The pressure accumulator is usually partially filledwith air. The emergency pump 580,' asnoted, is tapped in between supplypipe 566 and distribution pipe 564. An expansion or relief valve 561 maybe inserted between pipe 560 and pipe 564. The pressure-regulating valve510 has an inner chamber 51| provided with annular channels 512 and 513into which pipes 564 and 562 are respectively connected. Pipe 563, asalready noted, connects pump 510 with valve channel or groove 5|6a ofvalve 500. The valve plunger 514 is of generally cylindricalconstruction and is-provided with a central web 515 dividing the memberinto two chambers 516, 511. Chamber 516 is provided with a plurality ofholes or apertures 516a adapted,

upon appropriate movement of the plunger, to

establish fluid contact between pipes 564, 562 and valve chamber 51 Aspring 51 Ia may be inserted in chamber 516 and acts to apply pressureon plunger 514. An apron portion 516b is adapted to overliechannel orgroove 512 in the valve body and prevent ow of liquid through pipe 564.The plunger is actuated by foot pedal 518 fulcrumed to an auxiliaryplunger 5180i, whichlis tted in main plunger 514. The member 518'/isprovided with a spiral spring 518 b disposed therein. 518 is secured toor held in position by means of `a retaining spring 519 so thatconnections are vestablished between pipes 563 and 564.v

The pedal full pressure developed by pump 565, is; applied with lockingpins 556 in notch 550, the flow of the piston valve 53| is moved againto locked hydraulic operating fluid through pipes 563 and 564, is cut oiby the plunger 53|. If the valve plunger 53| is moved into the` secondposition with one of the pins 556 in the notch 55|, line 564 is,connected to pipe 503 and line 563 is connected to pipe 50|. In thisposition it will be seen that pressure is applied to the left side ofeach of plungers 51d and |26. Simultaneously pipe 504 is connected topipe 5|9 and pipe 502 is connected to pipe 5|1. This connection connectsthe right side of each of the clutch operating plungers to the returnpipe 560. With this operation the two double clutches of the geartransmission are engaged in one position. If valve piston 53| is movedso that notch 552 is locked by pins 556, the pressure on plunger 51d isreversed and the plunger is shifted to the left. The plunger |26 remainsin the same position. If

position determined by notch 553 and pins 556, the pressure on plungers51d and y|26, is reversed. Plunger |26 moves to the left and plunger 51dmoves to the right; When the valve plunger' is again moved so that notch554 is engaged by pin 520 the pressure on plunger 51d is again reversedand the plunger pushed to the left. The plunger |26 will remain on theleft side. The ve locking notches on the valve plunger 53| determine thefive different and definite relative positions of the two plungers 51dand |26, which respond tothe diiferent ratios in the transmission. Ashere shown, the different positions are as follows:

If, for any reason, pressure on the first double clutch 50 is to bedecreased or nulliiied while the vehicle is in motion, or that thiscondition occurs on starting to allow the clutch to slide, suchcondition can be 'obtained by appropriate pressure on foot pedal 518.Under normal operating conditions plunger 514 is kept in the downposition by springs 518b and 519. In this position full hydraulic poweris applied on the plunger 514. However, this pressure is equalized `byspring 5181 When the foot pedal is actuated, this spring pressure isreleased and the hydraulic pressure in chamber 51| with the held ofauxiliary spring 51|a, pushes plunger 514 outwardly, thereby partiallyobstructing connection between pipes 564 and 563 and at the same timeconnectspipe 563 with pipe 562, through apertures 516a. This positionpermits a flow of fluid through pipe 562 to the return line 560. Thepressure in line 563 drops and, at the same time, the pressure onplunger 51d which is supplied by line 563,will also drop. The drop inpressure on plunger 51d is in direct proportion to the' pressure appliedon foot pedal 518. By pressing the pedal all the way down the pressureon 51d will be brought downto zero. From this it will be noted thatpedal 518 canbe used-directly in substantially the same manner as theregular clutch pedal of an 'automobile and with substantially the same,or better, nal results. A distinct improvement in operation alone, asaresult of the mechanism `iust described, resides in the fact that thevariation of pressure is distributed over a large portion of themovement and the foot pressure required is reduced. Infact, it will beseen that the valve member 510 functions, at leastiin part, as aservo-motor control means. As a result much smoother driving is secured,due to the absence of jerkiness in operation.

The pressure-regulating valve 510 may not only be operator-controlled,but may be operated automatically by suitable means such as acentrifugal regulator operating from the engine. Such a regulator can bedesigned and installed to operate in such a manner that with the engineidling, pressure is cut oil, but as soon as the engine is speeded uppressure may be applied to the clutch in proportion to the engine speed.In like manner the shift valve plunger 53| may be automatically operatedby a regulator driven from the rear of the vehicle with a speedcorresponding to the wheel speed of the vehicle. If the car speedincreases to a predetermined point, theA regulatorwill have enough forceto shift the valve member one notch, and as further increases in speedare registered, appropriate shifting of the valve member 53| may beeffected until top speed is attained. Conversely, as the car slows downthe spring-balancing regulator will have enough force to cause thetransmission to be shifted back to a lower speed. It is to be noted thatthe present invention comprehends the balancing of the weights andsprings of the operating parts here described, and entering into theautomatic shifting of gears. in such a way as to produce, or give riseto an appreciable difference in speed between the shifting to a higherspeed and the shifting back again to lower speeds, in order to providecomfortable driving. It is 'to be noted, further, that the automaticoperation of the shifting valve and regulating valve may be used incombination with manually operated valves in such a manner as to requiremanual operation'only in case of an emergency. It

is to be noted, further, that the features of the v present inventionpermit the adjusting of the automatic regulating valve so that thedriver can regulate the speed at which the clutch will engage whiledriving.

The automatic engine speed and car speed control of shifting, will bedescribed further hereinafter, with specific reference to theconstructions shown in Figs. 24 to 32, respectively.

In the drawings, and more particularly in Figs. 20 to 23, inclusive,there is shown an electric operating mechanism for two double clutches,such, for example, as may be applied and utilized in the control andoperation of the transmission shown in Fig. 6 and describedhereinbefore.

Referring more particularly to Fig. 20, there is shown more or lessdiagrammatically, the double clutch therefor. In this arrangement, theforward clutch 50a and rear clutch operating lever 240 are shownconnected to electric starting system 600 by means of a drum switch 620.The immediate and direct control of the input and output double clutchesis as follows. The clutchplate 54a of magnetically controlled `clutch50a is provided with the solenoid coils 50h and 52e,

, previouslydescribed, and with leads 50g and 50h. -In addition, aseparate ground or slip ring 50k issecured onto the cover plate 52 andserves as a common negative return for the current. The source ofelectric current designated generally by the numeral 600,

comprises the usual automobile.

